Elm seedlings are annoying but nearly unavoidable

Q. The Drake elm in my yard and those of the neighbors produce thousands of seeds every fall and I spend most of the years pulling the seedlings up. How do you control the problem?

A. Like you, most gardeners spend some time pulling out the Drake elm seedlings. This is one of the Chinese elm selections and all flower during the fall. They also seem to be a favorite food of squirrels that cut off the ends of the branches.

If only the squirrels liked the seeds more, but they don't, so many elm trees pop up throughout the year. There is no product labeled to stop the fall flowering and seed production so you have to deal with the seeds. You might try preventing their germination in shrub and flower beds with a preemergence herbicide that is applied to established plantings and found at garden centers. Even with this extra help you are probably going to be removing lots of seedlings.

Q. My landscape poinsettias are beautiful but they have grown much too tall. How can I produce lower growing plants for next year?

A. Start to reign in the poinsettia growth with a heavy pruning in mid March. It may seem severe, but cut tall plants back to within 18 inches of the ground. Then give them a first of the year feeding and keep the soil moist.

When the plants produce about a foot of growth, cut them back 4- to 6-inches. Repeat these prunings every time the poinsettias produce another foot of growth until the end of August. By late summer your plants should be four or more feet tall and ready to start the flowering process for the holidays. Continue to keep the soil moist and repeat the feedings every other month or use a slow release fertilizer as instructed on the label.

Q. Can a Christmas cactus be transplanted now or is it best to wait until the blooms are gone? Then how should it be replanted?

A. Christmas cactuses are a bit finicky and don't like sudden changes which can cause them to drop their blooms. Why not enjoy the flowers now and then give your plant a new container early in the new year? First you have to decide if the plant needs a new container as the plants like to be a bit pot-bound. Unless the root system is filling the container, you can probably skip transplanting your cactus.

The month of March, when new growth begins, is a good time to move the Christmas and related holiday cactus to a new container. Select a clean pot about an inch larger in size. Then use a well-drained potting soil to fill in around the root ball. Do needed pruning at this time and continue normal care into the new year.

Q. I have been trying to grow head lettuce for three years and all I get are curly leaves. A friend told me to tie up the outer leaves. Will this work?

A. Tying up the leaves is going to give you a bunch of leaf lettuce but not the head of lettuce you are looking for. Good head lettuce starts with the right variety, like Great Lakes, most commonly found in the seed racks at garden centers. Then you need to start the seeds during the cooler weather. Now should be a good time for lettuce of all types. Keep the plantings moist and feed every 3 to 4 weeks. The plantings know what to do and won't need assistance to form the heads but it will take about 90 days to get a head of lettuce.

Q. Our pineapples, in containers, are growing well but the leaves are turning reddish purple. What do you recommend?

A. Try increasing the feedings to pop out the good color. Plants in containers can have the nutrients washed out by frequent waterings which your email mentioned was every 2 to 3 days. When the plants are making active growth a feeding with a water soluble fertilizer, every 2 to 3 weeks is needed. Or, you could use one of the slow release fertilizers that meters out the nutrients over several months.

If the purplish look occurs during the cooler months, the leaf change may be due to cold. Normally this occurs when temperatures dip near or below freezing. Since your plants are in containers, moving them to a warmer spot would help prevent discoloration due to winter weather.